Problem with the calibration of ad7755

I am a student and working on a project to measure the DC energy and power ICs AD7755 and I want to ask how to calibrate the integrated circuit I see that different combinations of outputs S0 and S1 and SCF to obtain a different value of the measurement. Is there a difference in the binding of the scheme except that exclude high-pass filter. What other features does this integrated circuit in DC measurements?

However, like you have mentioned, HPF must be disabled by keeping pin 2 at logic 0, for DC inputs. Due to the inherent ADC offsets in the two channels, the power/energy result will have a DC error (page 12 of datasheet). This offset will vary from one IC to another and also over temperature. Figure 14 shows offset distribution over many ICs, at 25C.